The present invention relates to a medication pump and a cartridge for use in a medication pump, and methods for using the same. More particularly, the present invention is particularly useful in the context of portable medication pumps that automatically discharge medication from a medication cartridge.
Various ambulatory or portable medical devices are known for treating patients at a remote site away from the caregiver or clinician office. One example of an ambulatory medical device is a drug delivery device, such as a drug pump, for providing periodic or continuous drug delivery to the patient when the patient is away from the caregiver's office. Ambulatory drug pumps are shown for example in U.S. Pat. Nos. 4,559,038, 4,731,058, 5,531,697, 5,389,078 and 5,695,473, the disclosures of which are hereby incorporated by reference. Drug pumps may be used to deliver insulin and many other medications.
Medication pumps are known that use a piston-like arrangement to push medication out of a cylindrical medication reservoir. The cylindrical medication reservoir may be provided within a cylindrical barrel, where a plunger pushes medication out of the reservoir, and may be called a syringe or cartridge. Drug pumps typically have a delivery conduit for connecting to the patient's body for delivery of the drug. An infusion set typically includes the delivery conduit, an access device for attaching the delivery conduit to the patient's body and an attachment device for attaching the delivery conduit to a medication cartridge. Improved structures and methods are needed for filling medication cartridges, loading medication cartridges, and sensing conditions within medication pumps.